Blood vessels and airway development in normal and congenital diaphragmatic hernia lungs

Publication

Publication

The phenotypic expression of congenital diaphragmatic hernia results in major difficulties
to standardize the treatment and the order of treatment modalities in the individual patient.
As a result even today the treatment of patients with congenital diaphragmatic hernia is
"trial and error" based on general assumptions with regards to the amount of pulmonary
hypoplasia, the unpredictability of the pulmonary vascular response as well as the
vulnerability of the lung parenchyma on different forms of ventilatory support.
As a consequence numerous authors have tried to modulate pulmonary vascular growth
by either surgical or chemical means in an attempt to have the fetus born with more
mature lungs. The variety of animal models as well as different approaches such as the antenatal use of corticosteroids, tracheal obstruction of variable length and definitive
"repair" of the diaphragmatic defect have been practiced.
Besides the pulmonary hypoplasia the response of the pulmonary vasculature on stress in
the postnatal period as well as the unpredictability of the result of attempts to modulate
pulmonary vascular tone has resulted in a variety of treatment modalities for pulmonary
hypertension.
In contrast to the suggested decreased nitric oxide synthase level in rodent and sheep
models of CDH, the use of inhaled nitric oxide has not resulted in a significant
improvement in survival rate.
Although the morphology of the pulmonary vasculature has been documented for many
decades consisting of medial hypoplasia, adventitional thickening and peripheral
extension of the muscular coat, still the question is unanswered whether the altered
morphology of the pulmonary vascular bed is the result of a developmental arrest or a
disease specific event. Up till now no data are available in humans to reach a definitive
answer.

Publication of this thesis was supported by: The Turkish Ministry of Health for a scholarship in Pediatric Surgical Intensive Care, Ankara, Turkey. The David Vervat Foundation, Rotterdam, The Netherlands.